I just got a 50mm AIS. I love it - built well, nice focus ring, super sharp. It seems, however, many think portraits are too hard with manual focus. I used to do that on my Nikon APS-C body(ies) with a 50 1.8 D lens. Sometimes I missed focus I guess - but it didn't seem to slow me down that much. It seems like a good decision to get the Nikon 50 1.8 G. But I just bought this AIS lens... What do you guys think? Should I spring for the other lens? Should I buy something else like an old 105 2.5 pre-AI? Thanks!